1. Technical Field
The embodiments disclosed herein relate to a power regenerative converter and a power conversion apparatus.
2. Related Art
A power regenerative converter is conventionally known as a power regeneration apparatus. A power regenerative converter is arranged, for example, between an inverter device for controlling a motor and a three-phase AC power supply. Upon deceleration of the motor, electric power is supplied from the motor to the power regenerative converter through the inverter device. The power regenerative converter converts the power into AC power by switching elements, and supplies the AC power to the three-phase AC power supply.
Known as conduction modes of the power regenerative converter are a PWM control mode and a 120-degree conduction mode. In such conduction modes, the switching element is switched to output voltage. Hence, the output voltage contains a high-frequency component. Therefore, a filter is provided between the three-phase AC power supply and the switching elements in the power regenerative converter. The filter reduces the influence of the high-frequency component to smooth input/output currents.
Such a filter includes a reactor and a capacitor. Hence, the filter becomes a cause of the occurrence of a resonance phenomenon. With respect to this, for example, in a power regenerative converter described in JP-A-2006-340466, a damping resistor is added to an LCL filter to suppress the resonance phenomenon.